A honeycomb structure is widely used as a filter for purifying exhaust gas of an internal combustion engine, such as a diesel particulate filter (for example, refer to Patent Literature 1). Since soot removed from exhaust gas deposits in a honeycomb structure, filter regeneration needs to be performed by burning the soot every certain period of time. In order to burn the soot, it is necessary simply to light the soot by supplying large amounts of combustion exhaust gas at high-temperature and burn out the soot.
The honeycomb structure may be broken by combustion heat of the soot during the filter regeneration, and thus, the honeycomb structure is required to have high thermal shock resistance. Patent Literature 1 describes, in a honeycomb structure having a structure in which a plurality of segment parts is connected by a connection part, the honeycomb structure whose thermal shock resistance is increased by adjusting strength of the connection part.